Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Caribou ME
553 am EDT Friday Jul 11 2014
high pressure will build east from the Great Lakes tonight...cross
the region Friday through Saturday...then move east Sunday. A weak
front will approach the area late Sunday.
Near term /through tonight/...
adjusted cloud cover with regards to cirrus shield moving through
down east and reduced lows tonight slightly. Otherwise...no
changes were made.
high pressure brings sunny skies...continued low humidity and
pleasant temperatures in the 70s today. Winds will be generally
light today with gusts reaching around 15 miles per hour in northern
Aroostook and less southward. A weak upper trough may bring
occasionally broken cumulus towards the Saint John valley by early
afternoon...but little moisture will be available for cumulus
elsewhere. A cirrus shield down east early this morning will move
out later in the morning. The highest temperatures will be down
east with a few 80f readings possible. Another cool dry night is
on tap tonight with lows in the upper 40s to around 50f in
northern zones and low 50s elsewhere. &&
Short term /Saturday through Sunday/...
the weekend gets off to a nice start as high pressure only slowly
slides east of the region. Return flow will mean slightly warmer
and just a bit more humid conditions. The dew points will still
remain in the reasonably comfortable 50s. Expect high temperatures in the
l/M 80s from interior downeast north into The Crown of Maine. A
developing sea breeze in the afternoon will keep temperatures cooler
along the coast. An upper low in eastern Manitoba drops into
Ontario sun with a surface low to develop in the diffluent flow
ahead of the upper low near the southern tip of James Bay. Clouds
will be on the increase Sat night with a few showers and storms
possible sun...especially in the afternoon across western and
northern Maine. The models all drive a fairly vigorous lead
shortwave across the region sun. Much of the downeast region will
likely remain dry...especially across Washington County.
Stronger return flow and more cloud cover will keep temperatures a bit
cooler than Sat...but it will be more muggy.
Long term /Sunday night through Thursday/...
warm...muggy & unsettled sums up at least the first half of the week.
A large upper low across the western Great Lakes at 12z Monday tracks
across the Great Lakes and into Quebec Wednesday. Showers and
thunderstorms are likely at times with the best chance of strong
to severe storms Tuesday PM as the upper low and surface cold front get
closer to the area and provide some additional upper level
support. The models diverge with significant ensemble spread by
Wednesday. The operational GFS is the fastest moving the cold front
through...and would have it in the Gulf of Maine by Wednesday evening. The
European model (ecmwf) is much slower and would keep the threat of showers going
right into Thursday. There is a lot of ensemble spread and forecast
confidence is not high on either solution at this point. There is
also some hint that low pressure develops along the front to our south
which would slow down the front and keep the chance of showers
going longer. For now have a chance of showers and have confined any
isolated thunderstorm to the downeast region Wednesday. Drier and less
humid weather is expected in the wake of the front...but again the
timing is highly uncertain.
Aviation /09z Friday through Tuesday/...
near term: VFR
Short term: VFR Sat. Low stratus and patchy fog are possible late
Sat night into Sun morning at kbhb and kbgr due to the return
flow around the departing surface high. Highly variable conditions
sun-Tuesday with showers and thunderstorms at times along with patchy
fog. The lowest ceilings will likely be downeast in patchy fog and
in any heavier shower and thunderstorm activity.
near term: no fog...light winds and seas around 2 to 3 feet.
Short term: a long duration of S-SW flow starts Sat and continues
through at least Tuesday. The wind is not expected to reach Small Craft Advisory
levels...but the seas will slowly build with time and may reach 5-6
feet by late Monday night or Tuesday. The wnawave guidance looks way too
high for the pattern and have cut the seas back by 2-3 feet Tuesday and
Tuesday night. It appears that the seas are too high because the wind
speeds are also too strong.